JPH07131808A - Chrominance noise reduction device - Google Patents

Abstract

PURPOSE:To obtain the device which reduces a decrease in resolution, vertical color slurring, and trailing in a moving picture even when noise reduction effect is increased by switching the output signals of a line correlation type noise reduction (line NR) means and a frame NR means with the output signal of a motion detecting circuit. CONSTITUTION:A chrominance signal applied to a chrominance component input terminal 1 is demodulated by a demodulating means 2 to generate a demodulated color difference signal. This color difference signal is inputted to the line NR circuit 3, frame NR circuit 4, and motion detecting circuit 5 respectively. The color difference signals having noises reduced by the line NR circuit 3 and frame NR circuit 4 are inputted to a switching means 6 and outputted by selecting the frame NR circuit 4 when it is considered that an image is still or the line NR circuit 3 when it is considered that the image is in motion. The selected color difference signal is inputted to a demodulating means 7 and outputted as a chrominance signal again from a chrominance signal output terminal 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to noise reduction of a color signal of a television signal.

[0002]

FIG. 42 shows, for example, Japanese Patent Laid-Open No. 59-17580.
FIG. 1 is a block diagram showing a conventional noise suppressor for television signals shown in Japanese Patent Laid-Open Publication No. 101-101, in which 101 is an input terminal, 102 is a frame memory, 103 is an output terminal,
4 is a subtraction circuit, 105 is an addition circuit, and 106 is a fixed storage device. The television signal A applied to the input terminal 101 is applied to the subtraction circuit 104 together with the output signal B of the frame memory 102, and the difference signal D = AB is output. The difference signal D is applied to the fixed storage device (memory) 106 as an address signal. Various values are recorded in each address in the fixed storage device 106, and 0 is recorded in an address whose absolute value of the difference signal D is larger than a certain number D0. When the value of the difference signal D is given to the storage device 106, a value corresponding to the address is obtained as an output Z, this output Z is added to the adder circuit 105, and the addition result A + Z is output to the output signal Y.
As a result, it is taken out from the output terminal 103. Since Z = 0 when the difference signal D is large, the output of the adder 105 is Y =
It becomes A. That is, the input signal A is directly output for the moving image portion. On the other hand, when the difference signal D has a value close to zero (smaller than the constant value D0), that is, in a portion considered to be a still portion of the image of the television, when the difference signal D is positive, that is, A> B, the fixed storage device. The negative (Z <0) memory content is read from 106 and added to the adder circuit 105. Therefore, the value of the output signal Y is Z from A
Acts to reduce the absolute value of, and the difference signal is negative, ie D <
Even when it is 0, the above-mentioned reverse operation is performed, so that the input signal A is output as it is as an output signal, which is not the immediate response at the time of the previous motion signal (greater than the predetermined value D), but AK (AB).
= (1-K) A + KB or-{(1-K) A + K
The output signal of B} is output, and as a result, random noise is suppressed.

[0003]

Since the conventional television signal noise reduction apparatus is constructed as described above, for example, noise is not reduced in the moving image portion, and the moving image is judged only by the subtractor. In the case of a noise reduction device that uses frame correlation and is difficult to make a strict determination, there is a problem such as trailing of moving images, which is a harmful effect, such as a phenomenon in which a white ball is displayed with a white tail, and the like. It was In addition, other noise reduction devices using line correlation have problems such as deterioration in resolution and vertical color sag.

The present invention has been made in order to solve the above-mentioned problems, and even if the noise reduction effect is enhanced, the deterioration of resolution, vertical color drift, and television with less trailing in moving images. The object is to obtain a signal, especially a color signal noise reduction device. Another object of the present invention is to obtain a color signal noise reduction device in which even a motion detection circuit having a simple structure has less adverse effects due to malfunction.

[0005]

According to a first aspect of the present invention, there is provided a color signal noise reduction device, wherein a color difference is obtained by inputting demodulation means for demodulating a color signal of a television signal into a color difference signal and a color difference signal of the demodulation means. There are provided two NR means, a line NR means for reducing noise from the line correlation of signals and a frame NR means for inputting color difference signals to reduce noise from the frame correlation of color difference signals. The switching is performed based on the output signal of the signal motion detection circuit.

A color signal noise reduction device according to a second aspect of the present invention is the color signal noise reduction device according to the first aspect, further comprising a frame NR according to the output signal of the motion detection circuit.
The value of the coefficient unit that determines the noise reduction effect of the means is made variable.

A color signal noise reduction device according to a third aspect of the present invention is the color signal noise reduction device according to the first aspect, wherein the value of a coefficient unit that determines the noise reduction effect of the line NR means is further changed by the output signal of the motion detection circuit. It is the one.

A color signal noise reduction apparatus according to a fourth aspect of the present invention is the color signal noise reduction apparatus according to the first aspect, further comprising a coefficient unit value and a frame for determining the noise reduction effect of the line NR means by the output signal of the motion detection circuit. The value of the coefficient unit that determines the noise reduction effect of the NR means is made variable.

According to a fifth aspect of the present invention, there is provided a color signal noise reduction apparatus which comprises a line NR means for inputting a color signal to reduce noise from the line correlation of the color difference signal and a line NR means for receiving the color difference signal and determining the frame correlation of the color difference signal. Two NR means of frame NR means for reducing noise are provided, and both output signals are mixed by a mixing ratio determined by an output signal of the motion detection circuit.

A color signal noise reduction device according to a sixth aspect of the present invention is the color signal noise reduction device according to the fifth aspect, further comprising a frame NR according to the output signal of the motion detection circuit.
The value of the coefficient unit that determines the noise reduction effect of the means is made variable.

A color signal noise reduction device according to a seventh aspect of the present invention is the color signal noise reduction device according to the fifth aspect, wherein the value of a coefficient unit that determines the noise reduction effect of the line NR means is further changed by the output signal of the motion detection circuit. It is the one.

A color signal noise reduction device according to an eighth aspect of the present invention is the color signal noise reduction device according to the fifth aspect, further comprising a line NR according to an output signal of a motion detection circuit.
Value of coefficient multiplier and frame NR for determining noise reduction effect of means
The value of the coefficient unit that determines the noise reduction effect of the means is made variable.

According to a ninth aspect of the present invention, there is provided a color signal noise reduction device, wherein a demodulation means for demodulating a color signal of a television signal into a color difference signal and the color difference signal of the demodulation means are input to perform line correlation of the color difference signal. The line NR means for reducing noise from the relationship and the frame NR for reducing the noise from the frame correlation of the color difference signals by inputting the color difference signals as well.
Two NR means, a motion detection circuit for inputting the color difference signal to detect the movement of the color difference signal, and a saturation degree detection circuit for detecting the saturation degree of the color signal by inputting the color signal from the input terminal. The output signals of both NR means are switched by the output signal of the motion detection circuit and the output signal of the saturation detection circuit.

A color signal noise reduction device according to a tenth aspect of the present invention is the color signal noise reduction device according to the ninth aspect, further comprising the output signal of the motion detection circuit and the output signal of the saturation detection circuit to reduce the noise of the frame NR means. The value of the coefficient unit that determines is variable.

The color signal noise reduction apparatus according to the invention of claim 11 is the color signal noise reduction apparatus of claim 9, further comprising the output signal of the motion detection circuit and the output signal of the saturation detection circuit to reduce the noise of the line NR means. The value of the coefficient unit that determines is variable.

A color signal noise reduction device according to a twelfth aspect of the present invention is the color signal noise reduction device according to the ninth aspect, wherein the noise reduction effect of the line NR means is further provided by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. The value of the coefficient unit that determines the noise reduction effect of the frame NR means is made variable.

According to a thirteenth aspect of the present invention, there is provided a color signal noise reduction device in which a line NR means for inputting a color difference signal to reduce noise from a vertical correlation of the color difference signal and a line NR means for inputting the color difference signal and determining a frame correlation of the color difference signal. Two NR means of frame NR means for reducing noise, a motion detection circuit for inputting a color difference signal to detect the movement of the color difference signal, and a color signal from an input terminal for detecting the saturation of the color signal. And a saturation detection circuit for outputting the output signals of both NR means to the modulation means using a mixing means for mixing the output signals of the NR means with a mixing ratio determined by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. It is the one.

A color signal noise reduction device according to a fourteenth aspect of the present invention is the color signal noise reduction device according to the thirteenth aspect, in which the noise reduction effect of the frame NR means is further provided by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. The value of the coefficient unit that determines is variable.

A color signal noise reduction device according to a fifteenth aspect of the present invention is the color signal noise reduction device according to the thirteenth aspect, wherein the noise reduction effect of the line NR means is further provided by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. The value of the coefficient unit that determines is variable.

A color signal noise reduction device according to a sixteenth aspect of the present invention is the color signal noise reduction device according to the thirteenth aspect, wherein the noise reduction effect of the line NR means is further provided by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. And the value of the coefficient unit that determines the noise reduction effect of the frame NR means is variable.

[0021]

In the color signal noise reduction device according to the present invention, the output of the line NR means is selected in the case of a moving image, and the output of the frame NR means is selected in the case of a still image. The vertical sagging, which is a harmful effect, is inconspicuous because it appears only in the moving image, and the frame NR
The trailing of the moving image, which is an adverse effect of the means, is not conspicuous because the output signal of the frame NR means is selected only in the still image.

In addition to the function of claim 1, the color signal noise reduction device in the invention of claim 2 increases the value of the coefficient unit that determines the noise reduction effect of the frame NR means in the case of a completely still image, and makes a minute movement. In such a case, by lowering the value of the coefficient unit that determines the noise reduction effect, the adverse effect of the frame NR means is not noticeable even for minute movements, and the noise reduction effect in a complete still image can be enhanced.

In addition to the function of the first aspect, the color signal noise reduction device according to the third aspect of the invention increases the value of the coefficient unit that determines the noise reduction effect of the line NR means in the case of a very large motion, In the case of motion, by lowering the value of the coefficient unit that determines the noise reduction effect, it is possible to enhance the noise reduction effect in a moving image having a large motion without the harmful effect of the line NR means in ordinary motion being conspicuous. .

In addition to the function of claim 1, the color signal noise reduction device in the invention of claim 4 increases the value of the coefficient unit that determines the noise reduction effect of the frame NR means in the case of a complete still image, and makes a minute movement. If there is, the value of the coefficient unit that determines the noise reduction effect is lowered. Also, in the case of a very large motion, the value of the coefficient that determines the noise reduction effect of the line NR means is increased, and in the case of normal motion, the value of the coefficient device that determines the noise reduction effect is decreased, so that any motion Even in such a case, the adverse effects of the frame NR means and the line NR means are not noticeable, and the noise reduction effect can be enhanced.

In the color signal noise reduction apparatus according to the invention of claim 5, the output of the line NR means is dominant in the case of a moving image, and the output of the frame NR means is dominant in the case of a still image. The vertical color sag which is a problem of the line NR means is not visible because it appears only in the moving image, and the trailing of the moving image which is a problem of the frame NR means is mainly selected only when the output signal of the frame NR means is a still image. It does not appear because it is not done. Line NR means and frame NR
Since the means are mixed by the mixing means, the switching between the both becomes inconspicuous.

In the color signal noise reduction device according to the invention of claim 6, in addition to the action of claim 5, in the case of a completely still image, the value of the coefficient unit that determines the noise reduction effect of the frame NR means is increased to make a minute movement. In such a case, by lowering the value of the coefficient unit that determines the noise reduction effect, the adverse effect of the frame NR means is not noticeable even for a minute movement, and the noise reduction effect of the complete still image can be enhanced.

In addition to the function of claim 5, the color signal noise reduction device in the invention of claim 7 increases the value of the coefficient unit that determines the noise reduction effect of the line NR means in the case of a very large motion, In the case of motion, by lowering the value of the coefficient unit that determines the noise reduction effect, it is possible to enhance the noise reduction effect in a moving image having a large motion without the harmful effect of the line NR means in ordinary motion being conspicuous. .

In addition to the effect of the fifth aspect, the color signal noise reduction device in the eighth aspect of the present invention increases the value of the coefficient unit that determines the noise reduction effect of the frame NR means in the case of a completely still image, and makes a minute movement. If there is, the value of the coefficient unit that determines the noise reduction effect is lowered. Further, in the case of a very large motion, the value of the coefficient unit that determines the noise reduction effect of the line NR means is increased, and in the case of a normal motion, the value of the coefficient unit that determines the noise reduction effect is decreased, so that any movement is performed. Even in the case, the adverse effects of the frame NR means and the line NR means are not noticeable, and the noise reduction effect can be enhanced.

In the color signal noise reduction apparatus according to the invention of claim 9, the output of the line NR means is selected in the case of a moving image, and the output of the frame NR means is selected in the case of a still image. The harmful vertical color sag is not visible because it appears only in the moving image, and the trailing of the moving image, which is an adverse effect of the frame NR means, is inconspicuous because the output signal of the frame NR means is selected only in the still image. When the saturation level of the color signal is detected by the saturation level detection circuit and the saturation level is extremely low, the output of the line NR means is forcibly selected. Also, there is no harmful effect of the frame NR means.

In addition to the effect of the ninth aspect, the color signal noise reduction apparatus according to the tenth aspect of the present invention increases the value of the coefficient unit that determines the noise reduction effect of the frame NR means in the case of a completely still image, and makes it small. When there is motion, the value of the coefficient unit that determines the noise reduction effect is lowered, so that the effect of the frame NR means is not noticeable even for a minute motion, and the noise reduction effect in a complete still image can be enhanced. Further, when the saturation degree is large, the value of the coefficient unit that determines the noise reduction effect of the frame NR means is increased, and when the saturation degree is relatively small, the value of the coefficient unit that determines the noise reduction effect is decreased, whereby the saturation degree is increased. Even if is small and it is difficult to detect the motion, the harmful effect can be reduced.

The color signal noise reduction device according to the invention of claim 11 has the function of claim 9 and, in the case of a very large motion, increases the value of a coefficient unit that determines the noise reduction effect of the line NR means, In the case of motion, by lowering the value of the coefficient unit that determines the noise reduction effect, it is possible to enhance the noise reduction effect in a moving image having a large motion without the harmful effect of the line NR means in ordinary motion being conspicuous. . Further, when the saturation degree is large, the value of the coefficient unit that determines the noise reduction effect of the line NR means is increased, and when the saturation degree is relatively low, the value of the coefficient unit that determines the noise reduction effect is decreased, whereby the saturation degree is increased. Even if is small and it is difficult to detect the motion, the harmful effect can be reduced.

In addition to the function of claim 9, the color signal noise reduction device in the invention of claim 12 increases the value of the coefficient unit that determines the noise reduction effect of the frame NR means in the case of a complete still image, and makes a minute movement. If there is, the value of the coefficient unit that determines the noise reduction effect is lowered. Further, in the case of a very large motion, the value of the coefficient unit that determines the noise reduction effect of the line NR means is increased, and in the case of a normal motion, the value of the coefficient unit that determines the noise reduction effect is decreased, so that any movement is performed. Even in the case, the adverse effects of the frame NR means and the line NR means are not noticeable, and the noise reduction effect can be enhanced. When the degree of saturation is high, the frame NR means and the line NR
Even if the degree of saturation is small and it is difficult to detect motion, the value of the coefficient unit that determines the noise reduction effect of the means is increased, and when the degree of saturation is relatively small, the value of the coefficient unit that determines the noise reduction effect is decreased. The harmful effect can be reduced.

In the color signal noise reduction device according to the invention of claim 13, the output of the line NR means is dominant in the case of a moving image, and the output of the frame NR means is dominant in the case of a still image. The vertical color sag, which is an adverse effect of the line NR means, is not visible because it appears only in the moving image, and the trailing of the moving image, which is an adverse effect of the frame NR means, is selected only when the output signal of the frame NR means is a still image. Because it is not noticeable. Further, when the saturation degree of the color signal is detected by the saturation degree detection circuit and the saturation degree is very small, the mixture ratio of the output of the line NR means is forcibly increased so that the movement detection circuit detects a light color which is difficult to detect. The frame NR means does not have any adverse effect on the movement. Further, since the line NR means and the frame NR means are mixed by the mixing means, the switching of both is inconspicuous.

In addition to the effect of the thirteenth aspect, the color signal noise reduction apparatus according to the fourteenth aspect of the invention increases the value of the coefficient unit that determines the noise reduction effect of the frame NR means in the case of a completely still image, and makes it small. When there is motion, the value of the coefficient unit that determines the noise reduction effect is lowered, so that the effect of the frame NR means is not noticeable even for a minute motion, and the noise reduction effect in a complete still image can be enhanced. Further, when the saturation degree is large, the value of the coefficient unit that determines the noise reduction effect of the frame NR means is increased, and when the saturation degree is relatively small, the value of the coefficient unit that determines the noise reduction effect is decreased, whereby the saturation degree is increased. Even if is small and it is difficult to detect the motion, the harmful effect can be reduced.

In addition to the effect of the thirteenth aspect, the color signal noise reduction device according to the fifteenth aspect of the present invention increases the value of the coefficient unit that determines the noise reduction effect of the line NR means in the case of a very large motion, and In the case of motion, by lowering the value of the coefficient unit that determines the noise reduction effect, it is possible to enhance the noise reduction effect in a moving image having a large motion without the harmful effect of the line NR means in ordinary motion being conspicuous. .
Further, when the saturation degree is large, the value of the coefficient unit that determines the noise reduction effect of the line NR means is increased, and when the saturation degree is relatively low, the value of the coefficient unit that determines the noise reduction effect is decreased, whereby the saturation degree is increased. Even if is small and it is difficult to detect the motion, the harmful effect can be reduced.

In the color signal noise reduction device according to the sixteenth aspect of the present invention, in addition to the action of the thirteenth aspect, in the case of a completely still image, the value of the coefficient unit that determines the noise reduction effect of the frame NR means is increased to make a minute movement. If there is, the value of the coefficient unit that determines the noise reduction effect is lowered, and if the movement is very large, the value of the coefficient unit that determines the noise reduction effect of the line NR means is increased, and in the case of normal movement By lowering the value of the coefficient unit that determines the noise reduction effect, the adverse effect of the frame NR means and the line NR means is not noticeable in any movement, and the noise reduction effect can be enhanced. If the degree of saturation is high, the frame NR means and the line N
When the value of the coefficient unit that determines the noise reduction effect of the R means is set to be high and the saturation degree is relatively small, the value of the coefficient unit that determines the noise reduction effect is set to be low so that the saturation degree is small and motion detection is difficult. However, the harmful effect can be reduced. Therefore, the function of reducing the color signal noise works best.

[0037]

EXAMPLES Example 1. An embodiment of the invention of claim 1 will be described with reference to the drawings. In FIG. 1, 1 is a color signal input terminal, 2
Is a demodulation means, 3 is a line NR circuit, 4 is a frame NR circuit, 5 is a motion detection circuit, 6 is a switching means, 7 is a modulation means, and 8 is a color signal output terminal. The color signal applied to the color signal input terminal 1 becomes a color difference signal demodulated by the demodulation means 2. This color difference signal is input to the line NR circuit 3, the frame NR circuit 4, and the motion detection circuit 5, respectively. The color difference signals whose noise has been reduced by the line NR circuit 3 and the frame NR circuit 4 are input to the switching means 6, respectively,
Either is selected by the output signal of the motion detection circuit 5. The criteria to be selected will be described later with reference to FIG. The selected color difference signal is input to the modulation means 7 and again output from the color signal output terminal as a color signal.

FIG. 2 shows an embodiment of the line NR circuit 3 in FIG. In FIG. 2, 9 is a color difference signal input terminal, 10 is a subtractor, 11 is a coefficient unit, 12 is a 1-line delay device, 13 is a second subtractor, and 14 is a color difference signal output terminal. Color difference signal applied to color difference signal input terminal 9 and 1-line delay device 1
The output signal of 2 is input to the subtractor 10 and a difference signal is obtained. This difference signal is input to the coefficient unit 11. The input / output characteristics of the coefficient unit are shown in FIG. The output signal of the coefficient unit and the original color difference signal are input to the second subtractor 13, and the difference signal is output from the color difference signal output terminal 14. The difference signal is also input to the 1-line delay unit 12.

FIG. 3 shows an embodiment of the frame NR circuit 4 in FIG. The operation of FIG. 3 is the same as that of FIG. 2 except that the 1-line delay unit in FIG.

FIG. 4 shows an embodiment of the motion detection circuit 5 in FIG. In FIG. 4, 9 is a color difference signal input terminal and 15 is 1
A frame delay device, 16 is a subtractor, 17 is a low-pass filter, 18 is an absolute value circuit, and 19 is a motion signal output terminal. The color difference signal applied to the color difference signal input terminal 9 is input to the subtractor 16 together with the output signal of the 1-frame delay unit 15, and the difference signal is obtained. A signal obtained by extracting a high-frequency component, which is considered to be sudden noise, from this difference signal by a low-pass filter is output from the motion signal output terminal 19 as a motion signal.

FIG. 5 shows an example of the input / output characteristics of the coefficient unit 11. If the input X is −D0 ≦ X ≦ D0, the output Y is Y
= KX (0 <K ≦ 1) and the input X is X ≦ −D0 or D0 ≦ X, the output Y is 0.

FIG. 6 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit and the operation of the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of this motion detection circuit is less than a certain value, that is, when it is considered that the image is stationary, the switching means changes the frame NR.
The circuit is selected and output. When the output voltage of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the switching means selects and outputs the line NR circuit.

Example 2. An embodiment of the invention of claim 2 will be described with reference to FIG. The basic configuration is the same as that of FIG. 1, except that the output signal of the motion detection circuit is input to the frame NR circuit together with the selection of the switching means.

FIG. 8 shows an embodiment of the frame NR means 20 in FIG. The basic configuration is the same as that of FIG.
2 is different in that it has a noise reduction effect switching terminal 21 for controlling the constant in order to make the value of the coefficient unit that determines the noise reduction effect variable.

FIG. 9 shows an example of input / output characteristics of the coefficient unit 22. The coefficient unit 22 has, for example, two characteristics, and the input X is −
When D0 ≦ X ≦ D0, the output Y is Y = K1 · X (0 <K ≦ 1) in the curve (A) or Y = K2 · X (0 <K2 ≦ K1) in the curve (B). Yes, if the input X is X ≦ −D0 or D0 ≦ X, the output Y is 0.

FIG. 10 is an explanatory diagram of the operation of FIG. The operation of the output of the detection circuit, the frame NR circuit and the switching means when the image moves is as shown in the figure. When the image moves,
The motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is less than a certain value, that is, when the image is considered to be still, the frame NR circuit is selected and output by the switching means. When the output voltage of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the switching means selects and outputs the line NR circuit. Further, when the motion signal is not completely zero even when the frame NR circuit is selected, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. If the selected noise reduction effect is small and the motion signal is completely zero, that is, completely stationary, the coefficient unit 2 of FIG.
For 2, the constant of the coefficient unit 22 that determines the characteristic A in FIG. 9 is selected, and the noise reduction effect becomes large. That is, the coefficient of the coefficient unit 22 is changed in two steps in accordance with the amount of movement to change the line NR.
The output signal is smoothly switched from to frame NR.

Example 3. An embodiment of the invention of claim 3 will be described with reference to FIG. The basic configuration is the same as that of FIG. 1, except that the output signal of the motion detection circuit is input to the line NR circuit together with the selection of the switching means.

FIG. 12 shows an embodiment of the line NR circuit 23 shown in FIG. Although the basic configuration is the same as that of FIG. 3, the noise reduction effect switching terminal 2 for controlling the constant of the coefficient multiplier 22 in order to make the value of the coefficient multiplier that determines the noise reduction effect variable.
1 is different.

FIG. 13 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the operation of the line NR circuit and the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion.
When the voltage of the output of the motion detection circuit is less than a certain value, that is, when the image is considered to be still, the frame NR circuit is selected and output by the switching means. When the output voltage of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the switching means selects and outputs the line NR circuit. Line NR
If the voltage at the output of the motion detection circuit is less than a certain level even when the circuit is selected, that is, if the motion is considered to be slight, the coefficient unit 22 of FIG. When the constant is selected and the noise reduction effect is small and the voltage of the output of the motion detection circuit is higher than a certain level, that is, when the motion is very large, the coefficient unit 22 of FIG. A constant is selected so that the noise reduction effect becomes large. That is, the slope that determines the input / output characteristics of the coefficient unit, which is determined by the size of the constant of the coefficient unit in the line NR circuit, is changed to small or large according to the slow speed and the fast speed.

Example 4. An embodiment of the invention of claim 4 will be described with reference to the drawings. 14, the basic configuration is the same as that of FIG. 1, but the values of the coefficient units that determine the noise reduction effect of the line and frame NR circuits are both controlled based on the output signal of the motion detection circuit. The line and frame NR circuits are the same as in FIGS. 12 and 8, respectively.

FIG. 15 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the frame NR circuit, the line NR circuit, and the operation of the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is less than a certain value, that is, when the image is considered to be still, the frame NR circuit is selected and output by the switching means. When the voltage of the output of the motion detection circuit is higher than a certain value, that is, when the image is considered to be moving,
The line NR circuit is selected and output by the switching means. Further, even when the line NR circuit is selected, if the voltage of the output of the motion detection circuit is smaller than a certain level, that is, if the motion is considered to be slight, the coefficient unit 22 of FIG. When the constant of the device 22 is selected to reduce the noise reduction effect and the voltage of the output of the motion detection circuit is higher than a certain level, that is, when the motion is very large, the coefficient device 22 of FIG. The constant of the device 22 is selected so that the noise reduction effect becomes large. Further, even when the frame NR circuit is selected, when the voltage of the output of the motion detection circuit is not completely zero, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. When the constant of the unit 22 is selected to reduce the noise reduction effect and the voltage of the output of the motion detection circuit is completely zero, that is, when the unit is completely stationary, the coefficient unit 22 of FIG. The constant of is selected to increase the noise reduction effect.

Example 5. An embodiment of the invention of claim 5 will be described with reference to the drawings. 16, the basic configuration is the same as that of FIG. 1 except that mixing means is provided instead of the switching means.

FIG. 17 shows an embodiment of the mixing means 24 in FIG. In FIG. 17, reference numeral 25 is a hood color difference signal input terminal, 26 is a line color difference signal input terminal, 27 is a mixing ratio input terminal, 28 is a calculator for performing (1-K) calculation, 29 is a first multiplier, and 30 is Second multiplier, 31 is adder, 14
Is a color difference signal output terminal. Line color difference signal input terminal 2
6, the color difference signal (S2) and the mixing ratio input terminal 27
The mixing ratio signal (K) added to the above is added to the multiplier 30 and the output signal (K · S2) is obtained. The color difference signal (S3) applied to the frame color difference signal input terminal 25 and the mixing ratio signal (K, where 0 ≦
The output signal (1-
Both K) are output signals ((1--
K) and S3) are obtained. The output signal (K · S2 + (1-K) · S
3) is obtained.

FIG. 18 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit and the operation of the mixing means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit. That is, K has a small value. When the voltage of the output of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the mixing ratio of the output signal of the line NR circuit is increased by the mixing means. That is, K becomes a large value.

Example 6. An embodiment of the invention of claim 6 will be described with reference to the drawings. 19, the basic configuration is the same as that of FIG. 16, except that the output signal of the motion detection circuit is input to the frame NR circuit together with the selection of the mixing means.

FIG. 20 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the operation of the frame NR circuit and the mixing means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion.
When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit.
When the voltage of the output of the motion detection circuit is equal to or higher than a certain value, that is, when the image is considered to be moving, the mixing ratio of the output signal of the frame NR circuit is lowered by the mixing means. Further, when the voltage of the output of the motion detection circuit is not completely zero even when the frame NR circuit is mainly output, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. When the constant of the coefficient unit 22 to be determined is selected and the noise reduction effect becomes small and the motion signal is completely zero, that is, when the motion signal is completely stationary, the coefficient unit 22 of FIG. The noise reduction effect selected is increased.

Example 7. An embodiment of the invention of claim 7 will be described with reference to the drawings. 21, the basic configuration is the same as that of FIG. 16 except that the output signal of the motion detection circuit is input to the line NR circuit together with the selection of the mixing means.

FIG. 22 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the operation of the line NR circuit and the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion.
When the voltage of the output of the motion detection circuit is less than a certain value, that is, when it is considered that the image is stationary, the mixing means reduces the mixing ratio of the output signals of the line NR circuit. When the voltage of the output of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the mixing ratio of the output signal of the line NR circuit is increased by the mixing means. Furthermore, when the voltage of the output of the motion detection circuit is smaller than a certain level even when the line NR circuit is mainly output, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. When the constant of the coefficient unit 22 to be determined is selected and the noise reduction effect becomes small and the motion signal is higher than a certain level, that is, when the motion is very large, the coefficient unit 22 of FIG. A constant is selected so that the noise reduction effect becomes large.

Example 8. An embodiment of the invention of claim 8 will be described with reference to the drawings. 23, the basic configuration is shown in FIG.
However, the constants of the coefficient unit that determines the noise reduction effect of the line and frame NR circuits are both controlled based on the output signal of the motion detection circuit. The line and frame NR circuits are the same as in FIGS. 12 and 8, respectively.

FIG. 24 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the frame NR circuit, the line NR circuit and the operation of the mixing means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit. When the voltage of the output of the motion detection circuit is higher than a certain value, that is, when the image is considered to be moving,
The mixing means increases the mixing ratio of the output signals of the line NR circuit. Furthermore, when the voltage of the output of the motion detection circuit is smaller than a certain level even when the line NR circuit is mainly output, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. When the constant to be determined is selected and the noise reduction effect becomes small and the output voltage of the motion detection circuit is higher than a certain level, that is, when the motion is very large, the coefficient unit 22 of FIG. 12 selects the constant that determines the A characteristic of FIG. The noise reduction effect is increased. Furthermore, when the motion signal is not completely zero even when the frame NR circuit is mainly output, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. 8 selects the constant that determines the B characteristic of FIG. When the noise reduction effect becomes small and the motion signal is completely zero, that is, when the motion signal is completely stationary, the coefficient unit 22 of FIG.
A constant that determines the A characteristic of FIG. 9 is selected to increase the noise reduction effect.

Example 9. An embodiment of the invention of claim 9 will be described with reference to the drawings. In FIG. 25, the basic configuration is the same as that of FIG. 1, except that a color signal saturation detection circuit 32 is provided and the switching means is controlled by two signals, the output of the motion detection circuit and the output of the saturation detection circuit. different. The output of the demodulation means 2 may be used as the input of the saturation detection circuit 32.

FIG. 26 shows an embodiment of the saturation detection circuit 32 shown in FIG. In FIG. 26, 33 is a color signal input terminal, 34 is a first absolute value circuit, 35 is a first integrating circuit,
36 is a 1-frame delay device, 37 is a second absolute value circuit, 3
Reference numeral 8 is a second integrating circuit, and 39 is a minimum value selecting circuit. The color signal input to the color signal input terminal 33 is the absolute value circuit 34.
Is input to and rectified. Further, it is integrated by the integrating circuit 35 to obtain a saturation degree according to the amplitude of the color signal. The color signal is also delayed by one frame by the one-frame delay device, and the saturation degree of one frame before is obtained by the above procedure. The smaller of the current saturation and the saturation one frame before is output as the saturation.

FIG. 27 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the output of the saturation detection circuit and the operation of the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is less than a certain value, that is, when the image is considered to be still, the frame NR circuit is selected and output by the switching means. When the voltage of the motion signal exceeds a certain value, that is, when it is considered that the image is moving, the line NR circuit is selected and output by the switching means. However, if the output voltage of the motion detection circuit is above a certain value, that is, if the saturation is below a certain value even when it is considered that the image is moving, all the line NR circuits are selected and output by the switching means.

Example 10. An embodiment of the invention of claim 10 will be described with reference to the drawings. 28, the basic configuration is shown in FIG.
5 except that the output signals of the motion detection circuit and the saturation detection circuit are input to the frame NR circuit together with the selection of the switching means.

FIG. 29 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the output of the saturation detection circuit, the operation of the frame NR circuit and the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is less than a certain value, that is, when the image is considered to be still, the frame NR circuit is selected and output by the switching means. When the output voltage of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the switching means selects and outputs the line NR circuit. Further, even when the frame NR circuit is selected, if the saturation degree is small, the coefficient unit 22 of FIG. 8 selects a coefficient that determines the B characteristic of FIG. 9 to reduce the noise reduction effect, and if the saturation degree is large, the coefficient of FIG. A coefficient that determines the characteristic A of FIG. 9 is selected for the coefficient unit 22 to enhance the noise reduction effect.

Example 11. An embodiment of the invention of claim 11 will be described with reference to the drawings. In FIG. 30, the basic configuration is shown in FIG.
5 except that the output signals of the motion detection circuit and the saturation detection circuit are input to the line NR circuit together with the selection of the switching means.

FIG. 31 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the operation of the line NR circuit and the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is less than a certain value, that is, when the image is considered to be still, the frame NR circuit is selected and output by the switching means.
When the output voltage of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the switching means selects and outputs the line NR circuit. Furthermore, even when the line NR circuit is selected, if the degree of saturation is low,
When the coefficient unit 22 of FIG. 12 has a coefficient unit value that determines the B characteristic of FIG. 9 and the noise reduction effect is small and the saturation is large, the coefficient unit 22 of FIG. Is selected, the noise reduction effect is increased.

Example 12 An embodiment of the invention of claim 12 will be described with reference to the drawings. In FIG. 32, the basic configuration is shown in FIG.
5, except that the output signals of the motion detection circuit and the saturation detection circuit are input to the line and frame NR circuits together with the selection of the switching means.

FIG. 33 is an explanatory diagram of the operation of FIG. The operations of the output of the motion detection circuit, the output of the saturation detection circuit, the frame NR circuit, the line NR circuit and the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the output voltage of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the frame NR circuit is selected and output by the switching means. When the output voltage of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the switching means selects and outputs the line NR circuit. Further, even when the line NR circuit is selected, if the voltage of the output of the motion detection circuit is smaller than a certain level, that is, if the motion is considered to be slight, the coefficient unit 22 of FIG. 9 is selected when the voltage of the output of the motion detection circuit is higher than a certain level, that is, when the motion is very large, the coefficient unit 22 of FIG.
The value of the coefficient unit that determines the A characteristic of is selected, and the noise reduction effect is increased. Further, even when the frame NR circuit is selected, when the voltage of the output of the motion detection circuit is not completely zero, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. When the value of the coefficient is selected to reduce the noise reduction effect and the voltage of the output of the motion detection circuit is completely zero, that is, when the coefficient is constant, the coefficient unit 22 of FIG. Is selected, the noise reduction effect is increased. If the saturation is small even when the line NR circuit is selected, the coefficient unit 2 of FIG.
2, the value of the coefficient unit that determines the B characteristic of FIG. 9 is selected to reduce the noise reduction effect, and when the saturation degree is large, the coefficient unit 22 of FIG. 12 selects the value of the coefficient unit that determines the A characteristic of FIG. The noise reduction effect becomes large. Further, when the degree of saturation is small even when the frame NR circuit is selected, the coefficient unit 2 of FIG.
2, the value of the coefficient unit that determines the B characteristic of FIG. 9 is selected to reduce the noise reduction effect, and when the saturation degree is large, the coefficient unit 22 of FIG. 8 selects the value of the coefficient unit that determines the A characteristic of FIG. The noise reduction effect becomes large.

Example 13 An embodiment of the invention of claim 13 will be described with reference to the drawings. In FIG. 34, the basic configuration is the same as that of FIG. 25, except that mixing means is provided instead of the switching means. The output of the demodulation means 2 may be used as the input of the saturation detection circuit 32.

FIG. 35 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit and the operation of the mixing means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit. When the voltage of the output of the motion detection circuit is higher than a certain value, that is, when it is considered that the image is moving, the mixing ratio of the output signal of the line NR circuit is increased by the mixing means. Further, when the output voltage of the motion detection circuit is sufficiently small and the degree of saturation is small, the mixing means increases the mixing ratio of the output signals of the line NR circuit.

Example 14 An embodiment of the invention of claim 14 will be described with reference to the drawings. In FIG. 36, the basic configuration is shown in FIG.
4, except that the output signals of the motion detection circuit and the saturation detection circuit are input to the frame NR circuit together with the selection of the switching means.

FIG. 37 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the operation of the frame NR circuit and the mixing means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion.
When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit.
When the voltage of the output of the motion detection circuit is equal to or higher than a certain value, that is, when the image is considered to be moving, the mixing ratio of the output signal of the frame NR circuit is lowered by the mixing means. Further, when the motion signal is not completely zero even when the frame NR circuit is mainly output, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. 8 is the coefficient unit that determines the B characteristic of FIG. Value is selected and the noise reduction effect is small, and when the motion signal is completely zero, that is, when the motion signal is completely stationary, the coefficient unit 22 of FIG. 8 selects the value of the coefficient unit that determines the A characteristic of FIG. Grows larger. Further, the value of the coefficient that determines the noise reduction effect of the frame NR circuit is adaptively set to a large or small value according to the degree of the saturation level.

Example 15. An embodiment of the invention of claim 15 will be described with reference to the drawings. 38, the basic configuration is shown in FIG.
4, but the difference is that the output signals of the motion detection circuit and the saturation detection circuit are input to the line NR circuit together with the selection of the switching means.

FIG. 39 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the operation of the line NR circuit and the switching means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion.
When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit.
When the movement voltage is higher than a certain value, that is, when the image is considered to be moving, the mixing ratio increases the mixing ratio of the output signals of the line NR circuit. Further, even when the line NR circuit is mainly output, when the motion signal is smaller than a certain level, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG. 12 is the value of the coefficient unit that determines the B characteristic of FIG. Is selected, the noise reduction effect becomes small, and when the output voltage of the motion detection circuit is higher than a certain level, that is, when the motion is very large, the coefficient unit 22 of FIG. 12 selects the value of the coefficient unit that determines the A characteristic of FIG. The noise reduction effect is increased. Further, the coefficient that determines the effect of the line NR circuit is adaptively changed depending on the magnitude of the degree of saturation.

Example 16 An embodiment of the invention of claim 16 will be described with reference to the drawings. In FIG. 40, the basic configuration is shown in FIG.
Except that the output signals of the motion detection circuit and the saturation detection circuit are input to the line and frame NR circuits together with the selection of the switching means.

FIG. 41 is an explanatory diagram of the operation of FIG. The output of the motion detection circuit, the frame NR circuit, the line NR circuit and the operation of the mixing means when the image moves are as shown in the figure. When the image moves, the motion detection circuit outputs a certain voltage according to the motion. When the voltage of the output of the motion detection circuit is below a certain value, that is, when it is considered that the image is stationary, the mixing means increases the mixing ratio of the output signals of the frame NR circuit. When the voltage of the output of the motion detection circuit is higher than a certain value, that is, when the image is considered to be moving,
The mixing means increases the mixing ratio of the output signals of the line NR circuit. Further, even when the line NR circuit is mainly output, when the motion signal is smaller than a certain level, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG.
When the value of the coefficient that determines the B characteristic of FIG. 9 is selected and the noise reduction effect becomes small and the motion signal is higher than a certain level, that is, when the motion is very large, the coefficient unit 22 of FIG. The value of the determined coefficient is selected, and the noise reduction effect becomes large. Further, when the motion signal is not completely zero even when the frame NR circuit is mainly output, that is, when the motion is considered to be slight, the coefficient unit 22 of FIG.
When the value of the coefficient unit that determines the B characteristic of FIG. 9 is selected and the noise reduction effect becomes small, and the motion signal is completely zero, that is, when the motion signal is completely stationary, the coefficient unit 22 of FIG. 8 determines the A characteristic of FIG. The value of the coefficient unit is selected to increase the noise reduction effect.
Also, since the coefficients that determine the effect of the frame NR circuit and the line NR circuit are adaptively changed to be large and small according to the degree of saturation, the present embodiment has the most complicated control. Balance (NR due to movement and saturation)
Well-balanced noise reduction operation, that is, both NRs
The best mode operation in which the harmful effect of the means is not noticeable is performed.

[0078]

According to the first aspect of the present invention, the output signals of the line NR means and the frame NR means are switched by the output signal of the motion detection circuit, so that the adverse effects of both are inconspicuous.

According to the invention of claim 2, in addition to the effect of claim 1, by changing the value of the coefficient unit that determines the noise reduction effect in the frame NR means by the output signal of the motion detection circuit, a still image is obtained. Even if it is judged, it can be divided into finer still images and cases with slight movement,
There is an effect that the effect of the frame NR means can be enhanced in a completely still image without any adverse effect.

According to the invention of claim 3, in addition to the effect of claim 1, the value of the coefficient unit which determines the noise reduction effect of the line NR means by the output signal of the motion detection circuit is made variable, so that it is judged as a moving image. Even in such a case, it can be divided into a case where the movement is finer and a case where the movement is small, and there is an effect that the effect of the line NR means can be enhanced in a moving image with a large movement.

According to the invention of claim 4, the effect of claim 2 and the effect of claim 3 are combined.

According to the fifth aspect of the present invention, the output signals of the line NR means and the frame NR means are mixed by the output signal of the motion detection circuit, so that the adverse effects of both are inconspicuous. Further, there is an effect that the switching between the two becomes inconspicuous.

According to the invention of claim 6, in addition to the effect of claim 5, the noise reduction effect of the frame NR means is made variable by the output signal of the motion detection circuit, so that even when it is judged as a still image, it is more detailed. There is an effect that it can be divided into a completely still image and a case where there is a slight movement, and the effect of the frame NR means can be enhanced without any adverse effect in the completely still image.

According to the invention of claim 7, in addition to the effect of claim 5, the noise reduction effect of the line NR means is made variable by the output signal of the motion detection circuit, so that even if it is judged as a moving image, the motion is finer. Can be divided into the case of large motion and the case of small motion, and the effect of the line NR means can be increased in a moving image with large motion.

According to the invention of claim 8, the effect of claim 6 and the effect of claim 7 are combined.

According to the invention of claim 9, the output signals of the line NR means and the frame NR means are switched by the output signals of the motion detection circuit and the saturation detection circuit. This has the effect of avoiding malfunctions when saturation is difficult to detect and is small.

According to the tenth aspect of the invention, in addition to the effect of the ninth aspect, the noise reduction effect of the frame NR means is made variable by the output signals of the motion detection circuit and the saturation detection circuit. There is an effect that can be increased in a completely still image. Further, it is possible to reduce the adverse effect of the frame NR means even for a light color motion that is difficult to detect.

According to the eleventh aspect of the invention, in addition to the effect of the ninth aspect, the noise reducing effect of the line NR means is made variable by the output signals of the motion detecting circuit and the saturation detecting circuit, so that the effect of the line NR means is changed. There is an effect that can be made high in a moving image with a large motion. Further, it is possible to reduce the adverse effect of the line NR means even for a light color movement that is difficult to detect.

According to the twelfth aspect of the invention, it is possible to obtain the combined effect of the tenth aspect and the eleventh aspect.

According to the thirteenth aspect of the present invention, the output signals of the line NR means and the frame NR means are mixed by the output signals of the motion detection circuit and the saturation detection circuit, so that the adverse effects of both are inconspicuous. . Further, there is an effect that the switching between the two becomes inconspicuous. Further, there is an effect that a malfunction can be avoided in a case where it is difficult to detect a motion and the saturation degree is small.

According to the fourteenth aspect of the invention, in addition to the effect of the thirteenth aspect, the value of the coefficient unit that determines the noise reduction effect of the frame NR means is made variable by the output signals of the motion detection circuit and the saturation detection circuit. As a result, the effect of the frame NR means can be enhanced in a completely still image.
Further, it is possible to reduce the adverse effect of the frame NR means even for a light color motion that is difficult to detect.

According to the fifteenth aspect of the invention, in addition to the effect of the thirteenth aspect, the noise reduction effect of the line NR means is made variable by the output signals of the motion detection circuit and the saturation detection circuit, so that the effect of the line NR means is obtained. There is an effect that can be made high in a moving image with a large motion. Further, it is possible to reduce the adverse effect of the line NR means even for a light color movement that is difficult to detect.

According to the sixteenth aspect of the present invention, the effect of the fourteenth aspect and the effect of the fifteenth aspect can be obtained. Therefore, the effect of the present invention is the so-called most balanced feedback of motion information and saturation information in a well-balanced manner. A good noise reduction effect (the adverse effects of both NRs are small) is obtained, and as a result, the image quality is greatly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a color signal noise reduction device according to a first aspect of the invention.

FIG. 2 is a block diagram showing an embodiment of the line NR circuit in FIG.

3 is a block diagram showing an embodiment of a frame NR circuit in FIG.

FIG. 4 is a block diagram showing an embodiment of the motion detection device in FIG.

5 is a graph showing an input / output characteristic of an embodiment of the coefficient unit in FIG. 2 or FIG.

FIG. 6 is an explanatory diagram showing the movement of the image in FIG. 1, the output signal of the movement detection circuit, and the operation of the switching means.

FIG. 7 is a block diagram showing a color signal noise reduction device according to a second aspect of the invention.

8 is a block diagram showing an embodiment of the frame NR circuit in FIG.

9 is a graph showing the input / output characteristics of an embodiment of the coefficient unit in FIG.

10 is an explanatory diagram showing the motion of the image in FIG. 7, the output signal of the motion detection circuit, the operation of the frame NR circuit, and the operation of the switching means.

FIG. 11 is a block diagram showing a color signal noise reduction device according to a third aspect of the invention.

12 is a block diagram showing an embodiment of the line NR circuit in FIG.

13 is an explanatory diagram showing the movement of the image in FIG. 11, the output signal of the movement detection circuit, the operation of the line NR circuit, and the operation of the switching means.

FIG. 14 is a block diagram showing a color signal noise reduction device according to a fourth aspect of the invention.

15 is an explanatory diagram showing the motion of the image in FIG. 14, the output signal of the motion detection circuit, the operation of the frame NR circuit, the operation of the line NR circuit, and the operation of the switching means.

FIG. 16 is a block diagram showing a color signal noise reduction device according to a fifth aspect of the invention.

FIG. 17 is a block diagram showing an embodiment of the mixing means in FIG.

FIG. 18 is an explanatory diagram showing the motion of the image in FIG. 16, the output signal of the motion detection circuit, and the operation of the mixing means.

FIG. 19 is a block diagram showing a color signal noise reduction device according to a sixth aspect of the invention.

20 is an explanatory diagram showing the motion of the image in FIG. 19, the output signal of the motion detection circuit, the operation of the frame NR circuit, and the operation of the mixing means.

FIG. 21 is a block diagram showing a color signal noise reduction device according to a seventh aspect of the invention.

22 is an explanatory diagram showing the movement of the image in FIG. 21, the output signal of the movement detection circuit, the operation of the line NR circuit, and the operation of the mixing means.

FIG. 23 is a block diagram showing a color signal noise reduction device according to an eighth aspect of the invention.

24 is an explanatory diagram showing the motion of the image in FIG. 23, the output signal of the motion detection circuit, the operation of the frame NR circuit, the operation of the line NR circuit, and the operation of the mixing means.

FIG. 25 is a block diagram showing a color signal noise reduction device according to a ninth aspect of the invention.

FIG. 26 is a block diagram showing an embodiment of the saturation detection circuit in FIG. 25.

27 is an explanatory diagram showing the motion of the image in FIG. 25, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, and the operation of the switching means.

FIG. 28 is a block diagram showing a color signal noise reduction device according to the invention of claim 10;

29 is an explanatory diagram showing the motion of the image in FIG. 28, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, the operation of the frame NR circuit, and the operation of the switching means.

FIG. 30 is a block diagram showing a color signal noise reduction device according to the invention of claim 11;

31 is an explanatory diagram showing the motion of the image in FIG. 30, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, the operation of the line NR circuit, and the operation of the switching means.

FIG. 32 is a block diagram showing a color signal noise reduction device according to a twelfth aspect of the present invention.

33 is an explanatory diagram showing the motion of the image in FIG. 32, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, the operation of the frame NR circuit, the operation of the line NR circuit, and the operation of the switching unit.

FIG. 34 is a block diagram showing a color signal noise reduction device according to a thirteenth invention.

FIG. 35 is an explanatory diagram showing the motion of the image in FIG. 34, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, and the operation of the mixing means.

FIG. 36 is a block diagram showing a color signal noise reduction device of the invention of claim 14;

37 is an explanatory diagram showing the motion of the image in FIG. 36, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, the operation of the frame NR circuit, and the operation of the mixing means.

FIG. 38 is a block diagram showing a color signal noise reduction device according to a fifteenth aspect of the present invention.

39 is an explanatory diagram showing the motion of the image in FIG. 38, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, the operation of the line NR circuit, and the operation of the mixing means.

FIG. 40 is a block diagram showing a color signal noise reduction device according to a sixteenth aspect of the present invention.

41 is an explanatory diagram showing the motion of the image in FIG. 40, the output signal of the motion detection circuit, the output signal of the saturation detection circuit, the operation of the frame NR circuit, the operation of the line NR circuit, and the operation of the mixing means.

FIG. 42 is a block diagram showing a conventional color signal noise reduction device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 color signal input terminal 2 demodulation means 3 line NR circuit 4 frame NR circuit 5 motion detection circuit 6 switching means 7 modulation means 8 color signal output terminal 9 color difference signal input terminal 10 first subtractor 11 coefficient unit 12 1 line delayer 13 Second Subtractor 14 Color Difference Signal Output Terminal 15 1 Frame Delay Device 16 Subtractor 17 Low Pass Filter 18 Absolute Value Circuit 19 Motion Signal Output Terminal 20 Frame NR Circuit (Variable Noise Reduction Effect Type) 21 Noise Reduction Effect Switching Terminal 22 coefficient unit (variable coefficient type) 23 line NR circuit (variable noise reduction effect type) 24 mixing means 25 color difference signal input terminal (input from frame NR circuit) 26 color difference signal input terminal (input from line NR circuit) 27 mixing Ratio input 28 Operator (Y = 1-K) 29 First multiplier 30 Second multiplier 31 Adder 32 Sum degree detection circuit 33 Color signal input terminal 34 First absolute value circuit 35 First integration circuit 36 1 Frame delay device 37 Second absolute value circuit 38 Second integration circuit 39 Minimum value selection circuit 40 Saturation output terminal 101 Input Terminal 102 Frame Memory 103 Output Terminal 104 Subtraction Circuit 105 Addition Circuit 106 Fixed Storage Device

Claims (16)

[Claims] 1. A demodulation means for demodulating a color signal of a television signal into a color difference signal, and a line correlation noise reduction means for receiving the color difference signal from the demodulation means and reducing noise from the line correlation of the color difference signal ( Below line NR
Means) and frame-correlation-type noise reduction means (hereinafter referred to as frame NR) for inputting the color-difference signal from the demodulation means and reducing noise from the frame-correlation of the color-difference signal.
Means), a motion detecting circuit for detecting the motion of the color signal from the demodulating means, an output signal of the line NR means and an output signal of the frame NR means are switched and output by the output signal of the motion detecting circuit. A color signal noise reduction device comprising switching means and modulating means for modulating a color difference signal of an output signal of the switching means into a color signal. 2. The color signal noise reduction apparatus according to claim 1, wherein the value of a coefficient unit that determines the noise reduction effect of the frame NR means is variable according to the output signal of the motion detection circuit. 3. The color signal noise reduction device according to claim 1, wherein the value of a coefficient unit that determines the noise reduction effect of the line NR means is variable according to the output signal of the motion detection circuit. 4. The color signal noise reduction device according to claim 1, wherein the value of the coefficient unit that determines the noise reduction effect of the line NR means and the value of the coefficient unit that determines the noise reduction effect of the frame NR means are motion detection circuits. Color signal noise reduction device that can be changed according to the output signal of. 5. A demodulation means for demodulating a color signal of a television signal into a color difference signal, a line NR means for receiving the color difference signal from the demodulation means and reducing noise from a line correlation of the color difference signal, and the demodulation. A frame NR means for inputting the color difference signal from the means to reduce noise from the frame correlation of the color difference signal, a motion detection circuit for detecting the movement of the color signal from the demodulation means, an output signal of the line NR means and the above Mixing means for determining a mixing ratio of the output signal of the frame NR means by the output signal of the motion detection circuit, and mixing
A color signal noise reduction device comprising a modulation means for modulating the color difference signal of the output signal of the mixing means into a color signal. 6. The color signal noise reduction device according to claim 5, wherein the value of a coefficient unit that determines the noise reduction effect of the frame NR means is variable according to the output signal of the motion detection circuit. 7. The color signal noise reduction device according to claim 5, wherein the value of a coefficient unit that determines the noise reduction effect of the line NR means is variable according to the output signal of the motion detection circuit. 8. The motion detection circuit in the color signal noise reduction apparatus according to claim 5, and in particular, the value of the coefficient unit that determines the noise reduction effect of the line NR means and the value of the coefficient unit that determines the noise reduction effect of the frame NR means. Color signal noise reduction device that can be changed according to the output signal of. 9. A demodulation means for demodulating a color signal of a television signal into a color difference signal, a line NR means for receiving a color difference signal from the demodulation means and reducing noise from a line correlation of the color difference signal, and the demodulation. A frame NR means for inputting the color difference signal from the means to reduce noise from the frame correlation of the color difference signal, a motion detection circuit for detecting the movement of the color signal from the demodulation means, and a saturation degree of the color signal from the input terminal. And a switching means for switching between the output signal of the line NR means and the output signal of the frame NR means by the output signal of the motion detection circuit and the output signal of the saturation detection circuit, and the switching means. Signal noise reduction device provided with a modulation means for modulating the color difference signal of the output signal of 1. into a color signal. 10. The color signal noise reduction device according to claim 9, wherein the value of the coefficient unit that determines the noise reduction effect of the frame NR means is variable depending on the output signal of the motion detection circuit and the output signal of the saturation detection circuit. Color signal noise reduction device. 11. The color signal noise reduction device according to claim 9, wherein the value of the coefficient unit that determines the noise reduction effect of the line NR means is made variable by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. Color signal noise reduction device. 12. In the color signal noise reduction apparatus according to claim 9, motion detection is performed between the value of a coefficient unit that determines the noise reduction effect of the line NR means and the value of a coefficient unit that determines the noise reduction effect of the frame NR means. A color signal noise reduction device that is made variable by the output signal of the circuit and the output signal of the saturation detection circuit. 13. A demodulation means for demodulating a color signal of a television signal into a color difference signal, a line NR means for receiving the color difference signal from the demodulation means and reducing noise from a line correlation of the color difference signal, and the demodulation. A frame NR means for inputting the color difference signal from the means to reduce noise from the frame correlation of the color difference signal, a motion detection circuit for detecting the movement of the color signal from the demodulation means, and a saturation degree of the color signal from the input terminal. And a mixing means for determining the mixing ratio of the output signal of the line NR means and the output signal of the frame NR means by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. And a color signal noise reduction device comprising modulation means for modulating the color difference signal output from the mixing means into a color signal. 14. The color signal noise reduction device according to claim 13, wherein the value of a coefficient unit that determines the noise reduction effect of the frame NR means is made variable by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. Color signal noise reduction device. 15. The color signal noise reduction apparatus according to claim 13, wherein the value of a coefficient unit that determines the noise reduction effect of the line NR means is made variable by the output signal of the motion detection circuit and the output signal of the saturation detection circuit. Color signal noise reduction device. 16. The color signal noise reduction apparatus according to claim 13, wherein the value of the coefficient multiplier that determines the noise reduction effect of the line NR means and the value of the coefficient multiplier that determines the noise reduction effect of the frame NR means are set in the motion detection circuit. A color signal noise reduction device that is variable according to the output signal and the output signal of the saturation detection circuit.